Power amplification module

ABSTRACT

Provided is a power amplification module that includes: a first amplification circuit that amplifies a first signal and outputs the amplified first signal as a second signal; a second amplification circuit that amplifies the second signal and outputs the amplified second signal as a third signal; and a feedback circuit that re-inputs/feeds back the second signal outputted from the first amplification circuit to the first amplification circuit as the first signal. The operation of the first amplification circuit is halted and the first signal passes through the feedback circuit and is outputted as the second signal at the time of a low power output mode.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a power amplification module.

2. Description of the Related Art

A power amplification module is used in a mobile communication devicesuch as a cellular phone in order to amplify the power of a signal to betransmitted to a base station. In such a power amplification module, thegain may be switched in accordance with the output level in order toimprove the power addition efficiency. In the power amplificationcircuit disclosed in Japanese Unexamined Patent Application PublicationNo. 2002-151982 for example, the gain of the power amplification circuitis adjusted by controlling the bias in accordance with the output level.

Although the gain can be adjusted by controlling the bias, the width ofthe adjustable range is limited. In recent years, it has been demandedthat the gain be further reduced at the time of a low power output modein power amplification modules that operate in a high power output modeor a low power output mode, and it is difficult to realize such areduction by controlling only the bias. In addition, a configuration hasbeen considered in which a low power output mode amplification circuitand a high power output mode amplification circuit are providedseparately from each other and the signal paths are switched betweenusing a switch in accordance with the power output mode, but thecharacteristics are degraded by the presence of such a switch along thesignal paths.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure was made in light of such circumstances and it isan object thereof to reduce the gain at the time of a low power outputmode and prevent the degradation of the characteristics in a poweramplification module that operates in a high power output mode or a lowpower output mode.

A power amplification module according to a preferred embodiment of thepresent disclosure includes: a first amplification circuit thatamplifies a first signal and outputs the amplified first signal as asecond signal; a second amplification circuit that amplifies the secondsignal and outputs the amplified second signal as a third signal; and afeedback circuit that re-inputs/feeds back the second signal outputtedfrom the first amplification circuit to the first amplification circuitas the first signal. The operation of the first amplification circuit ishalted and the first signal passes through the feedback circuit and isoutputted as the second signal at the time of a low power output mode.

According to the preferred embodiment of the present disclosure, it ispossible to increase the size of a gain reduction at the time of a lowpower output mode and suppress the degradation of the characteristics ina power amplification module that operates in a high power output modeor a low power output mode.

Other features, elements, characteristics and advantages of the presentdisclosure will become more apparent from the following detaileddescription of the preferred embodiments of the present disclosure withreference to the attached drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates an example configuration of a transmission unit thatincludes a power amplification module according to an embodiment of thepresent disclosure;

FIG. 2 illustrates an example of the configuration of a poweramplification module;

FIG. 3 illustrates an example of a feedback circuit;

FIG. 4 illustrates another example of the configuration of the poweramplification module;

FIG. 5 illustrates another example of the configuration of the poweramplification module;

FIG. 6 illustrates another example of the configuration of the poweramplification module;

FIG. 7 illustrates another example of the configuration of the poweramplification module;

FIG. 8 illustrates another example of the configuration of the poweramplification module;

FIG. 9 illustrates another example of the configuration of the poweramplification module;

FIG. 10 illustrates another example of the configuration of the poweramplification module;

FIG. 11 illustrates another example of the configuration of the poweramplification module;

FIG. 12 illustrates an example of a feedback circuit; and

FIG. 13 illustrates another example of the configuration of the poweramplification module.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereafter, an embodiment of the present disclosure will be describedwhile referring to the drawings. FIG. 1 illustrates an exampleconfiguration of a transmission unit that includes a power amplificationmodule according to an embodiment of the present disclosure. Atransmission unit 100 is for example used in a mobile communicationdevice such as a cellular phone in order to transmit various signalssuch as speech and data to a base station. Although such a mobilecommunication device would also be equipped with a reception unit forreceiving signals from the base station, the description of such areception unit will be omitted here.

As illustrated in FIG. 1, the transmission unit 100 includes a modulator110, a power amplification module 120, a front end unit 130 and anantenna 140.

The modulator 110 modulates an input signal on the basis of a modulationscheme such as high speed uplink packet access (HSUPA) or long termevolution (LTE) and generates a radio frequency (RF) signal forperforming wireless transmission. The RF signal has a frequency ofaround several hundred MHz to several GHz, for example.

The power amplification module 120 amplifies the power of the RF signal(RF_(IN)) outputted from the modulator 110 up to the level that isrequired to transmit the RF signal to the base station, and outputs theamplified signal (RF_(OUT)). The power amplification module 120 operatesin a power output mode that corresponds to a power output mode controlvoltage V_(MODE). The power output mode may be a low power output mode(LPM) or a high power output mode (HPM), for example.

The front end unit 130 filters the amplified signal and switches areception signal received from the base station. The amplified signaloutputted from the front end unit 130 is transmitted to the base stationvia the antenna 140.

FIG. 2 illustrates an example of the configuration of the poweramplification module 120. A power amplification module 120A includespower amplification circuits PA1, PA2 and PA3, a feedback circuit 200,bias circuits 201, 202 and 203, inductors 211, 212 and 213, matchingnetworks (MN) 221, 222 and 223 and a bias control circuit 230.

The power amplification circuits PA1, PA2 and PA3 are circuits thatamplify an RF signal and are formed of amplification transistors. Theamplification transistors are for example bipolar transistors such asheterojunction bipolar transistors. The power amplification circuitsPA1, PA2 and PA3 of the power amplification module 120A form athree-stage amplification circuit. The power amplification circuit PA1(first amplification circuit) amplifies an input signal (first signal)and outputs the amplified signal (second signal). The poweramplification circuit PA2 (second amplification circuit) amplifies thesignal from the power amplification circuit PA1 (second signal) andoutputs the amplified signal (third signal). The power amplificationcircuit PA3 (third amplification circuit) amplifies the signal from thepower amplification circuit PA2 (third signal) and outputs the amplifiedsignal (fourth signal).

The feedback circuit 200 forms a feedback path from the output(collector) of the power amplification circuit PA1 to the input (base)of the power amplification circuit PA1. The feedback circuit 200 isprovided in order to adjust (reduce) the gain of the power amplificationcircuit PA1.

FIG. 3 illustrates an example of the feedback circuit 200. Asillustrated in FIG. 3, the feedback circuit 200 can be formed of aresistor 300 and a capacitor 301 (CR feedback circuit) connected inseries with each other between the output and the input of the poweramplification circuit PA1.

The configuration of the feedback circuit 200 illustrated in FIG. 3 ismerely an example and the configuration of the feedback circuit 200 isnot limited to this configuration. For example, the feedback circuit 200may instead be formed of a resistor (DC feedback circuit) as describedlater with reference to FIG. 12. However, since DC feedback is performedin the case where the feedback circuit 200 is formed of a resistor, itis necessary to provide a capacitor that is comparatively large in sizearound the feedback point (around point X in FIG. 3). Therefore, byadopting the configuration illustrated in FIG. 3 for the feedbackcircuit 200, an increase in the size of the power amplification module120A can be suppressed.

The bias circuits 201, 202 and 203 are circuits for supplying biascurrents to the power amplification circuits PA1, PA2 and PA3 and eachincludes a bias circuit transistor. Specifically, in the bias circuit201 (first bias circuit), a bias control voltage V_(BIAS1) is suppliedto the base of the bias circuit transistor and a bias current (firstbias current) that corresponds to the bias control voltage V_(BIAS1) isoutputted from the emitter of the transistor. The bias current outputtedfrom the bias circuit 201 is supplied to the base of the transistor thatforms the power amplification circuit PA1. Similarly, the bias circuit202 (second bias circuit) outputs a bias current (second bias current)that corresponds to a bias control voltage V_(BIAS2). Furthermore, thebias circuit 203 (third bias circuit) outputs a bias current (third biascurrent) that corresponds to a bias control voltage V_(BIAS3).

The matching networks 221, 222, 223 are circuits for matching impedancesbetween circuits. The matching networks 221, 222, 223 are formed usingcapacitors and inductors, for example.

The bias control circuit 230 outputs the bias control voltagesV_(BIAS1), V_(BIAS2) and V_(BIAS3) for controlling the bias currents.The bias control voltages V_(BIAS1), V_(BIAS2) and V_(BIAS3) aresupplied to the bias circuits 201, 202 and 203, respectively. The biascontrol circuit 230 controls the bias control voltages V_(BIAS1),V_(BIAS2) and V_(BIAS3) on the basis of the power output mode controlvoltage V_(MODE).

Specifically, the following settings are made. A voltage at which atransistor forming a bias circuit is switched on is defined as a highlevel and a voltage lower than this level is defined as a low level. Thebias control circuit 230 makes all of the bias control voltagesV_(BIAS1), V_(BIAS2) and V_(BIAS3) be at the high level at the time ofthe high power output mode. In addition, the bias control circuit 230makes the bias control voltages V_(BIAS2) and V_(BIAS3) be at the highlevel and makes the bias control voltage V_(BIAS1) be at the low levelat the time of the low power output mode.

An example of the operation of the power amplification module 120A willbe described.

In the case of the high power output mode, the bias control circuit 230makes all of the bias control voltages V_(BIAS1), V_(BIAS2) andV_(BIAS3) be at the high level. That is, the bias control circuit 230supplies the bias currents generated by the bias circuits 201, 202 and203 to the power amplification circuits PA1, PA2 and PA3, respectively.Thus, in the power amplification module 120A, all the poweramplification circuits PA1, PA2 and PA3 operate. Thus, the RF signal(RF_(IN)) is amplified by a three-stage amplification circuitconstituted by the power amplification circuits PA1, PA2 and PA3.

In the case of the low power output mode, the bias control circuit 230makes the bias control voltages V_(BIAS2) and V_(BIAS3) be at the highlevel and makes the bias control voltage V_(BIASI) be at the low level.In other words, the bias control circuit 230 supplies the bias currentsgenerated by the bias circuits 202 and 203 to the power amplificationcircuits PA2 and PA3, respectively, and halts the supply of a biascurrent to the power amplification circuit PA1. Thus, in the poweramplification module 120A, the power amplification circuits PA2 and PA3operate and the power amplification circuit PA1 is halted. Since thepower amplification circuit PA1 is halted, the RF signal inputted to thepower amplification circuit PA1 passes through the feedback circuit 200and is outputted to the power amplification circuit PA2. Therefore, theRF signal is amplified by a two-stage amplification circuit constitutedby the power amplification circuits PA2 and PA3.

Thus, in the power amplification module 120A, the gain can be made lowerin the case of the low power output mode than in the case of the highpower output mode since the power amplification circuit PA1 is halted inthe low power output mode. By halting the power amplification circuitPA1, the size of the gain reduction achieved at the time of the lowpower output mode can be made larger than that achieved when the size ofthe bias current is controlled. In addition, in the power amplificationmodule 120A, since there is no switch along the path of the RF signal,the degradation of the characteristics can be suppressed.

In the power amplification module 120A, it is also possible to make thesize of the gain reduction even larger by halting the supply of a biascircuit to some of a plurality of parallel-connected transistors(fingers) that form the power amplification circuit PA3 in the case ofthe low power output mode. The same applies to other embodimentsdescribed below.

In addition, in the power amplification module 120A, a feedback circuitmay be provided in the second stage and in the third stage.

Furthermore, although a three-stage amplification circuit has beenadopted in the power amplification module 120A, the number of the stagesof the amplification circuit is not limited to three, and a two-stageamplification circuit (configuration without power amplification circuitPA3) or an amplification circuit with four or more stages may beadopted.

FIG. 4 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120A illustrated in FIG. 2 aredenoted by the same symbols and the description thereof is omitted. Asillustrated in FIG. 4, a power amplification module 120B includes a biascontrol voltage generating circuit 400 and a switch 401 instead of thebias control circuit 230 of the power amplification module 120A.

The bias control voltage generating circuit 400 generates a bias controlvoltage V_(BIAS) for controlling a bias current. The bias controlvoltage V_(BIAS) is supplied to the bias circuits 201, 202 and 203. Thebias circuits 201, 202 and 203 supply a bias current that corresponds tothe bias control voltage V_(BIAS) to the power amplification circuitsPA1, PA2 and PA3, respectively.

The switch 401 (bias control circuit) controls the supply of the biascontrol voltage V_(BIAS) to the bias circuit 201 on the basis of thepower output mode control voltage V_(MODE).

Specifically, in the case of the high power output mode, the switch 401is turned on and the bias control voltage V_(BIAS) is supplied to thebias circuit 201. In addition, in the case of the low power output mode,the switch 401 is turned off and the supply of the bias control voltageV_(BIAS) to the bias circuit 201 is halted. The switch 401 can be formedof a MOSFET, for example. Other switches described later can besimilarly formed of a MOSFET, for example.

Since the details of the operation of the power amplification module120B are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 5 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120B illustrated in FIG. 4 aredenoted by the same symbols and the description thereof is omitted. Asillustrated in FIG. 5, a power amplification module 120C furtherincludes switches 402 and 403 in addition to the configuration of thepower amplification module 120B.

The switches 401, 402 and 403 (bias control circuits) respectivelycontrol the supply of the bias control voltage V_(BIAS) to the biascircuits 201, 202 and 203 on the basis of power output mode controlvoltages V_(MODE1) and V_(MODE2).

Specifically, in the case of the high power output mode, the switches401, 402 and 403 are all turned on. In this case, the bias controlvoltage V_(BIAS) is supplied to the bias circuits 201, 202 and 203. Inaddition, in the case of the low power output mode, the switch 401 isturned off and the switches 402 and 403 are turned on. In this case, thesupply of the bias control voltage V_(BIAS) to the bias circuit 201 ishalted.

Since the details of the operation of the power amplification module120C are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 6 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120B illustrated in FIG. 4 aredenoted by the same symbols and the description thereof is omitted. Asillustrated in FIG. 6, in a power amplification module 120D, the switch401 controls the supply of a bias current outputted from the biascircuit 201 to the power amplification circuit PA1 on the basis of thepower output mode control voltage V_(MODE).

Specifically, in the case of the high power output mode, the switch 401is turned on. In this case, a bias current is supplied to the poweramplification circuits PA1, PA2 and PA3 from the bias circuits 201, 202and 203, respectively. In addition, in the case of the low power outputmode, the switch 401 is turned off. In this case, the supply of the biascurrent to the power amplification circuit PA1 is halted.

Since the details of the operation of the power amplification module120D are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 7 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120C illustrated in FIG. 5 orthe power amplification module 120D illustrated in FIG. 6 are denoted bythe same symbols and the description thereof is omitted.

As illustrated in FIG. 7, in a power amplification module 120E, theswitches 401, 402 and 403 (bias control circuits) respectively controlthe supply of a bias current to the power amplification circuits PA1,PA2 and PA3 on the basis of the power output mode control voltagesV_(MODE1) and V_(MODE2).

Specifically, in the case of the high power output mode, the switches401, 402 and 403 are all turned on. In this case, a bias current issupplied to all of the power amplification circuits PA1, PA2 and PA3. Inaddition, in the case of the low power output mode, the switch 401 isturned off and the switches 402 and 403 are turned on. In this case, thesupply of the bias current to the power amplification circuit PA1 ishalted.

Since the details of the operation of the power amplification module120E are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 8 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120B illustrated in FIG. 4 aredenoted by the same symbols and the description thereof is omitted.

As illustrated in FIG. 8, a power amplification module 120F includesbias control voltage generating circuits 800 and 810 instead of the biascontrol voltage generating circuit 400 of the power amplification module120B. The bias control voltage generating circuit 800 generates a biascontrol voltage V_(BIAS1) to be supplied to the bias circuit 201. Thebias control voltage generating circuit 810 generates a bias controlvoltage V_(BIAS2) to be supplied to the bias circuits 202 and 203. Theswitch 401 controls the supply of a power supply voltage V_(CC) to thebias control voltage generating circuit 800 on the basis of the poweroutput mode control voltage V_(MODE).

Specifically, in the case of the high power output mode, the switch 401is turned on. In this case, a bias current is supplied to the poweramplification circuits PA1, PA2 and PA3 from the bias circuits 201, 202and 203, respectively. In addition, in the case of the low power outputmode, the switch 401 is turned off. In this case, the operation of thebias control voltage generating circuit 800 is halted and the supply ofthe bias current to the power amplification circuit PA1 is halted.

Since the details of the operation of the power amplification module120F are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 9 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120F illustrated in FIG. 8 aredenoted by the same symbols and the description thereof is omitted.

As illustrated in FIG. 9, in a power amplification module 120G, theswitch 401 controls the supply of a ground voltage to the bias controlvoltage generating circuit 800 on the basis of the power output modecontrol voltage V_(MODE).

Specifically, in the case of the high power output mode, the switch 401is turned on. In this case, a bias current is supplied to the poweramplification circuits PA1, PA2 and PA3 from the bias circuits 201, 202and 203, respectively. In addition, in the case of the low power outputmode, the switch 401 is turned off. In this case, the operation of thebias control voltage generating circuit 800 is halted and the supply ofthe bias current to the power amplification circuit PA1 is halted.

Since the details of the operation of the power amplification module120G are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 10 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120B illustrated in FIG. 4 aredenoted by the same symbols and the description thereof is omitted.

As illustrated in FIG. 10, in a power amplification module 120H, theswitch 401 controls the operation of the power amplification circuit PA1on the basis of the power output mode control voltage V_(MODE). Theswitch 401 is connected in series with the transistor that forms thepower amplification circuit PA1. At the time of the high power outputmode, the switch 401 is turned on and therefore the power amplificationcircuit PA1 operates. On the other hand, at the time of the low poweroutput mode, the switch 401 is turned off and therefore the operation ofthe power amplification circuit PA1 is halted. Thus, the operation ofthe power amplification circuit PA1 may be controlled by controlling thesupply of a ground voltage or a power supply voltage, rather than bycontrolling the supply of a bias current.

Since the details of the operation of the power amplification module120H are the same as those of the operation of the power amplificationmodule 120A, the description thereof is omitted.

FIG. 11 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120A illustrated in FIG. 2 aredenoted by the same symbols and the description thereof is omitted.

As illustrated in FIG. 11, a power amplification module 120J includes afeedback circuit 1100 instead of the feedback circuit 200 of the poweramplification module 120A. The feedback circuit 1100 (second feedbackcircuit) forms a feedback path from the output (collector) of the poweramplification circuit PA2 to the input (base) of the power amplificationcircuit PA2. The feedback circuit 1100 is provided in order to adjust(reduce) the gain of the power amplification circuit PA2.

FIG. 12 illustrates an example of the feedback circuit 1100. Asillustrated in FIG. 12, the feedback circuit 1100 can be formed of aresistor 1200 (DC feedback circuit) connected between the output and theinput of the power amplification circuit PA2. A capacitor 1210 can beprovided between the input of the power amplification circuit PA2 andthe resistor 1200, as illustrated in FIG. 12. The capacitor 1210 may bethe part of the matching network 221 or may be provided separate to thematching network 221.

The configuration of the feedback circuit 1100 illustrated in FIG. 12 ismerely an example and the configuration of the feedback circuit 1100 isnot limited to this configuration. For example, the feedback circuit1100 can be configured as a CR feedback circuit as illustrated in FIG.3. However, a DC feedback circuit is stable over a wider frequency band(particularly low frequency band) compared to a CR feedback circuit.Accordingly, by adopting the configuration illustrated in FIG. 12 forthe feedback circuit 1100, the characteristics of the poweramplification module 120J can be improved.

An example of the operation of the power amplification module 120J willbe described.

In the case of the high power output mode, the bias control circuit 230makes all of the bias control voltages V_(BIAS1), V_(BIAS2) andV_(BIAS3) be at the high level. That is, the bias control circuit 230supplies the bias currents generated by the bias circuits 201, 202 and203 to the power amplification circuits PA1, PA2 and PA3, respectively.Accordingly, all the power amplification circuits PA1, PA2 and PA3operate in the power amplification module 120J. Thus, the RF signal(RF_(IN)) is amplified by a three-stage amplification circuitconstituted by the power amplification circuits PA1, PA2 and PA3.

In the case of the low power output mode, the bias control circuit 230makes the bias control voltages V_(BIAS1) and V_(BIAS3) be at the highlevel and makes the bias control voltage V_(BIAS2) be at the low level.In other words, the bias control circuit 230 supplies the bias currentsgenerated by the bias circuits 201 and 203 to the power amplificationcircuits PA1 and PA3, respectively, and halts the supply of a biascurrent to the power amplification circuit PA2. Thus, in the poweramplification module 120J, the power amplification circuits PA1 and PA3operate and the power amplification circuit PA2 is halted. Since thepower amplification circuit PA2 is halted, the RF signal inputted to thepower amplification circuit PA2 passes through the feedback circuit 1100and is outputted to the power amplification circuit PA3. Therefore, theRF signal is amplified by a two-stage amplification circuit constitutedby the power amplification circuits PA1 and PA3.

Thus, in the power amplification module 120J, the gain can be made lowerin the case of the low power output mode than in the case of the highpower output mode since the power amplification circuit PA2 is halted inthe low power output mode. By halting the power amplification circuitPA2, the size of the gain reduction achieved at the time of the lowpower output mode can be made larger than that achieved when the size ofthe bias current is controlled. In addition, in the power amplificationmodule 120J, since there is no switch along the path of the RF signal,the degradation of the characteristics can be suppressed.

Furthermore, in the power amplification module 120J, since the operationof the first stage power amplification circuit PA1, which serves as theinput terminal of the RF signal, is not halted at the time of the lowpower output mode, the input impedance seen by RF_(IN) does not change.Therefore, the degradation of the voltage standing wave ratio (VSWR) canbe suppressed.

In the power amplification module 120J, it is also possible to make thesize of the gain reduction even larger by halting the supply of a biascircuit to some of a plurality of parallel-connected transistors(fingers) that form the power amplification circuit PA3 in the case ofthe low power output mode, similarly to as in the power amplificationmodule 120A. In particular, in the power amplification module 120J, whenthe operation of the second-stage power amplification circuit PA2 ishalted, the gain peak shifts toward the low-frequency side, but theinput capacitance of the third-stage power amplification circuit PA3 isreduced and the gain peak can be returned toward the high-frequency sideby halting the operation of the part of the third-stage poweramplification circuit PA3.

Furthermore, in the power amplification module 120J, a feedback circuitmay be provided in the first stage and in the third stage.

Furthermore, although a three-stage amplification circuit has beenadopted in the power amplification module 120J, the number of the stagesof the amplification circuit is not limited to three, and a two-stageamplification circuit (configuration without power amplification circuitPA3) or an amplification circuit with four or more stages may beadopted. In addition, the supply of a bias current can also becontrolled using a switch, similarly to as in the power amplificationmodules 120B to 120G.

FIG. 13 illustrates another example of the configuration of the poweramplification module 120. Constituent elements that are the same asthose of the power amplification module 120A illustrated in FIG. 2 orthe power amplification module 120J illustrated in FIG. 11 are denotedby the same symbols and the description thereof is omitted.

A power amplification module 120K includes a circuit for amplifying anRF signal (RF_(INH)) of a comparatively high frequency band (firstfrequency band) and a circuit for amplifying an RF signal (RF_(INL)) ofa comparatively low frequency band (second frequency band).

In the power amplification module 120K, the high-frequency-band RFsignal (RF_(INH)) is amplified using a configuration that is the same asthe power amplification module 120A illustrated in FIG. 2. Specifically,a bias control circuit 230H (first bias control circuit) controls biascontrol voltages V_(BIAS1H), V_(BIAS2H) and V_(BIAS3H) on the basis of apower output mode control voltage V_(MODEH) such that a poweramplification circuit PATH (first amplification circuit), a poweramplification circuit PA2H (second amplification circuit) and a poweramplification circuit PA3H (third power amplification circuit) alloperate in the case of the high power output mode. In addition, the biascontrol circuit 230H controls the bias control voltages V_(BIAS1H),V_(BIAS2H) and V_(BIAS3H) on the basis of the power output mode controlvoltage V_(MODEH) such that the operation of the power amplificationcircuit PA1H is halted and the RF signal RF_(INH) is outputted to thepower amplification circuit PA2H via the feedback circuit 200 (firstfeedback circuit) in the case of the low power output mode.

In the power amplification module 120K, the low-frequency-band RF signal(RF_(INL)) is amplified using a configuration that is the same as thepower amplification module 120J illustrated in FIG. 11. Specifically, abias control circuit 230L (second bias control circuit) controls biascontrol voltages V_(BIAS1L), V_(BIAS2L) and V_(BIAS3L) on the basis of apower output mode control voltage V_(MODEL) such that a poweramplification circuit PAIL (fourth amplification circuit), a poweramplification circuit PA2L (fifth amplification circuit) and a poweramplification circuit PA3L (sixth power amplification circuit) alloperate in the case of the high power output mode. In addition, the biascontrol circuit 230L controls the bias control voltages V_(BIAS1L),V_(BIAS2L) and V_(BIAS3L) on the basis of the power output mode controlvoltage V_(MODEL) such that the operation of the power amplificationcircuit PA2L is halted and an output signal of the power amplificationcircuit PAIL is outputted to the power amplification circuit PA3L viathe feedback circuit 1100 (second feedback circuit) in the case of thelow power output mode.

The power amplification module 120K is provided with thehigh-frequency-band bias control circuit 230H and the low-frequency-bandbias control circuit 230L, but a bias control circuit may be commonlyused for both the high frequency band and the low frequency band.

In addition, in the power amplification module 120K, it is also possibleto make the size of the gain reduction even larger by halting the supplyof a bias circuit to some of a plurality of parallel-connectedtransistors (fingers) that form the power amplification circuits PA3Hand PA3L in the case of the low power output mode, similarly to as inthe power amplification modules 120A and 120J.

In the power amplification module 120K, the power amplification circuitthat stops operating at the time of the low power output mode is thesecond-stage power amplification circuit PA2L in the low-frequency-bandcircuit. Therefore, since the first-stage power amplification circuitPAIL does not stop operating at the time of the low power output mode,the degradation of the voltage standing wave ratio can be suppressed.

On the other hand, the power amplification circuit that stops operatingat the time of the low power output mode is the first-stage poweramplification circuit PA1H in the high-frequency-band circuit. Althoughit is possible to make the power amplification circuit that stopsoperating at the time of the low power output mode be the second-stagepower amplification circuit PA2H similarly to as in thelow-frequency-band circuit, in this case, the gain peak would be shiftedtoward the low-frequency side when the operation of the poweramplification circuit PA2 is halted. The size of a change in the gainpeak increases as the frequency becomes higher due to the effect of theimpedance of a capacitor (Z=1/ωC) and the impedance of an inductor(Z=ωL). Consequently, by making the power amplification circuit thatstops operating at the time of the low power output mode in thehigh-frequency-band circuit be the first-stage power amplificationcircuit PA1H rather than the second-stage power amplification circuitPA2H, it is possible to suppress the degradation of the characteristics.

Exemplary embodiments of the present disclosure have been describedabove. In the power amplification module 120A, the gain can be greatlyreduced at the time of the low power output mode by halting theoperation of the first-stage power amplification circuit PA1 and causingthe RF signal to bypass the first-stage power amplification circuit PA1via the feedback circuit 200. In addition, since there is no switchalong the path of the RF signal, the degradation of the characteristicscan be suppressed. The same applies to the power amplification modules120B to 120G.

Furthermore, by configuring the feedback circuit 200 as a CR feedbackcircuit in the power amplification module 120A, an increase in the sizeof the power amplification module 120A can be suppressed compared to thecase where the feedback circuit 200 is configured as a DC feedbackcircuit. This is because in the case of DC feedback, two capacitors arerequired to prevent a DC voltage from flowing out toward RF_(in) and toprevent a DC voltage from flowing out toward the first-stage poweramplification circuit PA1 and since the two capacitors need to let theRF signal pass therethrough, the capacitances of the capacitors need tobe large. Consequently, compared with CR feedback, two capacitors havinga large capacitance (large in size) need to be used and an increase inthe size of the module occurs. In contrast, in the case of CR feedback,no DC voltage returning from the feedback circuit flows toward RF_(in)and therefore the DC voltage can be directly returned to RF_(in). Inorder to prevent the RF_(in) signal from entering the CR feedbackcircuit, the capacitance of the capacitor used in CR feedback needs tobe made small. As a result, comparing DC feedback and CR feedback,although two capacitors are needed in both types of feedback, the sizeof the capacitor in the CR feedback can be reduced. It is possible toreduce the size of the power amplifier module 120A.

Furthermore, in the power amplification module 120A, the size of thegain reduction can be increased by halting the operation of some of thetransistors (fingers) that form the third-stage power amplificationcircuit PA3 at the time of the low power output mode.

In addition, in the power amplification module 120J, the gain can begreatly reduced at the time of the low power output mode by halting theoperation of the second-stage power amplification circuit PA2 andcausing the RF signal to bypass the second-stage power amplificationcircuit PA2 via the feedback circuit 1100. In addition, since there isno switch along the path of the RF signal, the degradation of thecharacteristics can be suppressed. Furthermore, since the poweramplification circuit that is stopped at the time of the low poweroutput mode is the second-stage power amplification circuit PA2 ratherthan the first-stage power amplification circuit PA1, the degradation ofthe voltage standing wave ratio can be suppressed.

In addition, in the power amplification module 120J, the feedbackcircuit 1100 is configured to perform DC feedback, and therefore thedegradation of the characteristics can be suppressed over a widerfrequency band than in the case of CR feedback.

Furthermore, in the power amplification module 120A, the size of thegain reduction can be increased by halting the operation of some of thetransistors (fingers) that form the third-stage power amplificationcircuit PA3 at the time of the low power output mode.

In addition, in the power amplification module 120K, by halting theoperation of the first-stage power amplification circuit PA1H andcausing the RF signal to bypass the first-stage power amplificationcircuit PA1H via the feedback circuit 200 at the time of the low poweroutput mode in the high-frequency-band circuit, the same effect as inthe power amplification module 120A can be obtained. In addition, in thepower amplification module 120K, by halting the operation of thesecond-stage power amplification circuit PA2L and causing the RF signalto bypass the second-stage power amplification circuit PA2L via thefeedback circuit 1100 at the time of the low power output mode in thelow-frequency-band circuit, the same effect as in the poweramplification module 120H can be obtained.

In particular, in the power amplification module 120K, by making thepower amplification circuit that stops operating at the time of the lowpower output mode in the high-frequency-band circuit be the first-stagepower amplification circuit PA1H rather than the second-stage poweramplification circuit PA2H, it is possible to suppress the degradationof the characteristics.

The embodiments described above are for enabling easy understanding ofthe present disclosure and are not to be interpreted as limiting thepresent disclosure. The present disclosure can be modified or improvedwithout departing from the gist of the disclosure and the equivalents tothe present disclosure are also included in the present disclosure. Inother words, appropriate design modifications made to the embodiments byone skilled in the art are included in the scope of the presentdisclosure so long as the modifications have the characteristics of thepresent disclosure. For example, the elements included in theembodiments and the arrangements, materials, conditions, shapes, sizesand so forth of the elements are not limited to those exemplified in theembodiments and can be appropriately modified. In addition, the elementsincluded in the embodiments can be combined as much as technicallypossible and such combined elements are also included in the scope ofthe present disclosure so long as the combined elements have thecharacteristics of the present disclosure.

While preferred embodiments of the disclosure have been described above,it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the disclosure. The scope of the disclosure, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A power amplification module comprising: a firstamplification circuit amplifying a first signal and outputting theamplified first signal as a second signal; a second amplificationcircuit amplifying the second signal and outputting the amplified secondsignal as a third signal; and a feedback circuit re-inputting andfeeding back the second signal outputted from the first amplificationcircuit to the first amplification circuit as the first signal; whereinan operation of the first amplification circuit is halted and the firstsignal passes through the feedback circuit and is outputted as thesecond signal at the time of a low power output mode.
 2. The poweramplification module according to claim 1, wherein the feedback circuitis formed of a resistor and a capacitor connected in series with eachother.
 3. The power amplification module according to claim 1, furthercomprising: a third amplification circuit amplifying the third signaland outputting the amplified third signal as a fourth signal.
 4. Thepower amplification module according to claim 3, wherein the thirdamplification circuit includes a plurality of transistors connected inparallel with each other, and an operation of some of the plurality oftransistors of the third amplification circuit is halted at the time ofthe low power output mode.
 5. A power amplification module comprising: afirst amplification circuit amplifying a first signal and outputting theamplified first signal as a second signal; a second amplificationcircuit amplifying the second signal and outputting the amplified secondsignal as a third signal; a third amplification circuit amplifying thethird signal and outputting the amplified third signal as a fourthsignal; and a feedback circuit performing a feedback from an output ofthe second amplification circuit to an input of the second amplificationcircuit; wherein an operation of the second amplification circuit ishalted and the second signal passes through the feedback circuit and isoutputted as the third signal at the time of a low power output mode. 6.The power amplification module according to claim 5, wherein thefeedback circuit is formed of a resistor.
 7. The power amplificationmodule according to claim 5, wherein the third amplification circuitincludes a plurality of transistors connected in parallel with eachother, and an operation of some of the plurality of transistors of thethird amplification circuit is halted at the time of the low poweroutput mode.
 8. A power amplification module comprising: a firstamplification circuit amplifying a first signal of a first frequencyband and outputting the amplified first signal as a second signal; asecond amplification circuit amplifying the second signal and outputtingthe amplified second signal as a third signal; and a third amplificationcircuit amplifying the third signal and outputting the amplified thirdsignal as a fourth signal; a first feedback circuit performing afeedback from an output of the first amplification circuit to an inputof the first amplification circuit; a fourth amplification circuitamplifying a fifth signal of a second frequency band being lower thanthe first frequency band and outputting the amplified fifth signal as asixth signal; a fifth amplification circuit amplifying the sixth signaland outputting the amplified sixth signal as a seventh signal; a sixthamplification circuit amplifying the seventh signal and outputting theamplified seventh signal as an eighth signal; and a second feedbackcircuit performing a feedback from an output of the fifth amplificationcircuit to an input of the fifth amplification circuit; wherein anoperation of the first amplification circuit is halted and the firstsignal passes through the first feedback circuit and is outputted as thesecond signal at the time of a first low power output mode in a casewhere the first signal is inputted, and an operation of the fifthamplification circuit is halted and the sixth signal passes through thesecond feedback circuit and is outputted as the seventh signal at thetime of a second low power output mode in a case where the fifth signalis inputted.
 9. The power amplification module according to claim 8,wherein the first feedback circuit is formed of a resistor and acapacitor connected in series with each other, and the second feedbackcircuit is formed of a resistor.
 10. The power amplification moduleaccording to claim 8, wherein the third amplification circuit includes aplurality of transistors connected in parallel with each other, and anoperation of some of the plurality of transistors of the thirdamplification circuit is halted at the time of the first low poweroutput mode.
 11. The power amplification module according to claim 8,wherein the sixth amplification circuit includes a plurality oftransistors connected in parallel with each other, and an operation ofsome of the plurality of transistors of the sixth amplification circuitis halted at the time of the second low power output mode.
 12. The poweramplification module according to claim 2, further comprising: a thirdamplification circuit amplifying the third signal and outputting theamplified third signal as a fourth signal.
 13. The power amplificationmodule according to claim 6, wherein the third amplification circuitincludes a plurality of transistors connected in parallel with eachother, and an operation of some of the plurality of transistors of thethird amplification circuit is halted at the time of the low poweroutput mode.
 14. The power amplification module according to claim 9,wherein the third amplification circuit includes a plurality oftransistors connected in parallel with each other, and an operation ofsome of the plurality of transistors of the third amplification circuitis halted at the time of the first low power output mode.
 15. The poweramplification module according to claim 9, wherein the sixthamplification circuit includes a plurality of transistors connected inparallel with each other, and an operation of some of the plurality oftransistors of the sixth amplification circuit is halted at the time ofthe second low power output mode.
 16. The power amplification moduleaccording to claim 10, wherein the sixth amplification circuit includesa plurality of transistors connected in parallel with each other, and anoperation of some of the plurality of transistors of the sixthamplification circuit is halted at the time of the second low poweroutput mode.